The invention relates to a supporting frame for a panel comprising a peripheral structure for receiving an electrically active panel such as a photovoltaic cell panel. This supporting frame for a panel is intended, in particular, for supporting electrically active panels disposed on a wall of a building such as a roof or a façade.
In order to equip buildings such as houses with electricity generators which employ solar energy, sets of panels consisting of a plurality of photovoltaic cells are disposed, for example, on the roof of these buildings.
These panels generally consist of a stack of differing layers of glass, silicon, conductors and polymers. The sides of the generally square silicon cells can be as great as 200 mm. The cells are connected in series then bonded between two sheets of glass or between one sheet of glass and differing layers of polymer. By way of example, a module having a nominal voltage of 12 V is generally constructed by connecting 36 monocrystalline or polycrystalline cells in series. These assemblies of 36 cells are then connected in parallel. 72 silicon cells are thus used in the case of a 24 V module.
The front face of panels or modules of this type consists of glass, is directed toward the sun and allows radiation to pass through in such a way that it can interact with the silicon cells and generate electricity. This glass plate also has the function of protecting the photovoltaic cells from differing impacts. The back face of the modules or panels may be either opaque, consisting of a complex stack of polymers for protecting the cells from mechanical attack and corrosion, or transparent, in which case the front face is a glass plate.
These photovoltaic modules or panels are disposed on frameworks of which the uprights generally consist of connected aluminium profiles to impart mechanical strength thereto and to enable them to be fixed to the roof. In addition, the panels are connected to one another and to a distribution circuit for powering electrical loads.
In general, the connections are made at the back of the photovoltaic panels via bundles of cable extending below the photovoltaic panels. If the photovoltaic panels are transparent, these bundles of cable are particularly unsightly, and this is a drawback, in particular if the photovoltaic panels are to be placed on the façade of the building. In fact, transparent panels of this type may be used as means of ornamentation, and the presence of visible bundles of cable behind them, through the transparency, makes these panels unsuitable for such a use.
This problem may also be encountered with other electrically active panels such as electroluminescent panels or panels which may comprise elements such as flat screens.
In addition, the aluminium frameworks are fairly bulky owing to the poor mechanical properties of aluminium, and they may have corrosion characteristics which are not always satisfactory. The positioning thereof and, in particular, the production of the electrical connections are also labour-intensive.
Finally, in the event of heavy snowfall, aluminium frameworks may be pulled out by sliding sheets of snow.